Thermometer



vC. J. MANUEL ETV AL THERMOMETER Filed ovot. 5. 1926 July 12, 1927.

@wom/115014 4 fw. w.

MAA, MW

Patented July 1,2, 1927.

UNITED STATES' 1,635,680 P A'ri-:N'ry OFFICE.

CHARLES J. MANUEL AND WILLIAM H. LENTZ, F

snnmsnsvnmn, PENNSYLVANIA,

` ASSIGNORS TO UNITED STATES GAUGE COMPANY, 0I' NEW YORK, N. Y., A GOB.-

PORATION 0F IPENNSYLVANIA.

THERMOMETER.

Application med October 6, 1926. Serial No. 189,585.

is to reinforce, the strucnot only to stiien it in service but to enableit to hold its shape while being enameled.

Another obj ect is to so shape the shell that it will be adapted to becoated with a uniform coatingfof vitreous enamel.

Another object is to form the shell with a thimble whichpartiallyextends up over the face of.- the shell in order to reinsforce theshell. A

Another object is to form the thimble and shell so that the partscomprising the thermometer may be assembled and held in operativerelationship `)without the use of auxiliary plates, brackets, etc., suchas are frequently used in thermometers of this kind.

Another object is to so form the shell and thimble that the samestructure, slightly modified, may be used for both straight and angletype instruments. f

Another object is to incorporate the above objects and advantages ina'design suitable for pressed steel construction.

Further and other objects and advantages will be hereinafter set forthin panying speciication and claims, and shown in the drawings, which byway of illustration show what is now considered to be the preferredembodiment of the invention.

Fig. 1 shows a front view of the thermometer herein disclosed.

Fig. 2.is a cross-section on Fig. 1.

Fig. 3 is a perspective detail view of the thimble and lower end of theshell.

Fig. 4 is a cross-section on line 4--4 of line 2-2 of Fig. i.

Fig. 5 is a cross-sectional detail of 'an angle type.

The instrument is provided with a, body portion 10, threaded as at 12for ready attachment to the boiler.- The lower end of theI body portionhas a well-like portion 14 into i hich extends the bulb 16 on the lower:purpose of reinforcing and stiifeningR the accom-y end of thethermometer stem 20. The well 14 may be packed with suitableheat-conducting material 22.

Inserted in the upper end of member 10, and held in'position by setscrew 24, is the lower, tubular thimble portion 26, of shell 28. Theexposed portion of shell 28 i's shaped as shown in Figs. 2 and 4. It isprovided with a rearwardly extending `rim which extends along both sidesand across the top of the shell, merging at the bottom with thimble 26.The lower portion of shell 28 is also swelled outwardly at-32 for thethe shell against fore and aft stresses. ein! forcement 32 ispractically an extension of thimble 26 upwardly to overlap shell 28.Abm/extending from the upper end of 32 to a point near the top of shell28 is a narrow depression or groove 34 of substantially the same depthas ilanges 30.

The lrelationship of shell 28,l groove 34, and thimble 2 6 is such thatwhen the bulb of a straight thermometer is located centrally lin well 14the stem thereofrwill lie below the front surface of shell 28 in groove34, parallelthereto and only slightly out ot Contact therewith at therear and at bothl sides of the tube, as may best be seen in Fig. 4.

The upper e indicated at 36, away to form the opening passes stem 20.

Near the upper end of the tube a clip 40 serves to hold stem 20 inpropere operative, spaced relationship with groove 34. In its preferredform, clip 40 is simply a narrow strip of metal surrounding the stem,the ends of the strip passing through a hole in the rear of groove 34and being bent over to prevent their withdrawal.

A rubber washer 42 placed around stem 20 near the upper end of'thimbie26 serves d of groove 34 is closed as and the lower end is cut 38through which to resiliently support the lower end of the ful purpose.Shell 28 is usually coated with vitreous enamel. The process of applyingthe enamel requires that the material be heated to red heat, and it hasbeen found very difficult to prevent warping of the heated articlesduring the subsequent cooling operation, especially if the enamel isapplied to thin unsupported plane surfaces. The present deslgn providessuitable sup ort at the sides f shell 28 in the form of anges 30 andalso supplies the additional support required at the middle of theshell, in tie form of groove 34. These stiifening supports are providedwhile still maintaining a uniform thickness of metal, which is anotherimperative requirement for successful enameling.

Still another imperative requirement for successful enameling is lthatall enamel surfaces must have well rounded corners, otherwise enamelwill be thin on the corners and they will be a different color from therest of the surface. This feature is well taken care of in the resentdesign, all corners being Well roundrfid, so that the front of the shellwill be of uniform color.

Thermometer shells have in the past been formed ofcast iron to embodysome of the characteristics of the present design, but they have beenheavy, clumsy and costly as compared With the resent shell, which is aunitary structure ofp thin material, therefore light in Weight, neat inappearance, and cheap to manufacture.

A structure such as above described may be fabricated from separatepieces of metal joined together b welding or othervproces's.v

`but we prefer to orm the complete shell and thimble fromI a singlesheet of metal.

The front face of shell 28 is provided Y with the usual graduatedtemperature scale 44, which it will be noted is in a plane substantiallytangent to the front of the stem.

Thimble 26 is pressed from the same blank as shell 28, being formed incylindrical shape of proper diameter to slip inside the body portion 10.The thimble is left uuenameled.

Fig. 5 shows a modification of thimble 26 adapting it for an angle typeof instrument in which shell 28 stands at right anspecificallyillustrated and described but can be embodied in other forms withoutdeparture from its spirit.

e claiml. A shell for a thermometer comprising in combination, ametallic plate; a flange around the edge of said plate; a narrow groovealong the middle of said plate to accommodate the stem of thethermometer, said groove bein closed at one end and open at the otherend to allow the stem of the thermometer to pass through the end of saidgroove; and a cylindrical thimble axially aligned with said groove; saidplate, flange, groove, and thimble being of uniform thickness wherebythe shell is rendered suitable for finishing by the vitreous enamelprocess.

2. The invention set forth in claim 1 iu which a portion of the end ofsaid thimble extends over the end of the plate to which it is attachedfor the purpose of stifl'ening said shell.

3. The invention set forth in claim l in which the entire structure isformed from a single sheet of metal.

4f.V A thermometer comprising in combination, a thermometer stem and ashell supporting said stern; said shell comprising a metallic platehaving a flange around its edge; a narrow groove along the middle ofsaid plate to accommodate said stem` said groove being closed at one endand open at the other end to allow the stem to pass through the end ofsaid groove; and a cylindrical thimble axially aligned with said groove,said plate, flange, groove-and thimble being formed from a single sheetof thin metal.

In testimony whereof we hereto aliix our signatures.

CHARLES J. MANUEL. WILLIAM H. LENTZ.

